RRPP timers
When RRPP determines the link state of an Ethernet ring, it uses the following timers:
Hello timer
The Hello timer specifies the interval at which the master node sends Hello packets out of the primary port.
Fail timer
The Fail timer specifies the maximum delay of Hello packets sent from the primary port to the secondary port of the master node. If the secondary port receives the Hello packets sent by the local master node before the Fail timer expires, the ring is in Health state. Otherwise, the ring transits to Disconnect state.
In an RRPP domain, a transit node learns the Fail timer value on the master node through the received Hello packets. This ensures that all nodes in the ring network have consistent Fail timer settings.
Fast-Hello timer
The Fast-Hello timer specifies the interval at which the master node sends Fast-Hello packets out of the primary port.
Fast-Fail timer
The Fast-Fail timer specifies the maximum delay of Fast-Hello packets sent from the primary port to the secondary port of the master node. If the secondary port receives the Fast-Hello packets before the Fast-Fail timer expires, the ring is in Health state. Otherwise, the ring transits to Disconnect state.
A transit node cannot learn the Fast-Fail timer value on the master node through received Fast-Hello packets.
Fast-Edge-Hello timer
The Fast-Edge-Hello timer specifies the interval at which the edge node sends Fast-Edge-Hello packets out of the common port.
Fast-Edge-Fail timer
The Fast-Edge-Fail timer specifies the maximum delay of Fast-Edge-Hello packets from the common port of the edge node to the common port of the assistant edge node. If the assistant edge node receives the Fast-Edge-Hello packets from the common port before the Fast-Edge-Fail timer expires, the ring is in Health state. Otherwise, the ring transits to Disconnect state.